Commodity Price Versus Investment: A Contract-Level Ledger

Identify the thing being measured

A spot reference describes a particular commodity grade, location, and timing. Owning physical goods can involve storage, transport, insurance, and financing, so a percentage spot-price change is not automatically a net investment return. A futures contract references specified delivery or settlement terms at a named maturity. Different maturities are separate instruments, not one asset whose purchase price is simply reset each month.

CFA Institute's Introduction to Commodities and Commodity Derivatives distinguishes physical markets, derivatives, and components of futures-based returns. The CFTC describes contract terms and daily marking to market. These sources support the accounting distinctions; the numerical ledger below comes entirely from invented assumptions. No exchange contract specifications, actual commodity observations, or historical index returns are represented by the example.

Set up a hypothetical two-contract sequence

Begin with USD 100,000 account capital and a long futures position covering 1,000 fictional units. Contract A is entered at 84 per unit while the spot reference is 80. At the assumed roll point, spot is 86 and A is closed at 86. The realized cumulative change on A is 2 per unit, or positive USD 2,000, leaving account value USD 102,000 before excluded items.

At that same point, open Contract B at 90 for the same 1,000-unit quantity. Later, close B at 86 while spot remains 86. B contributes negative USD 4,000, leaving USD 98,000. Assume zero interest on account cash, no fees, no slippage, and no financing expense. Daily variation-margin movements are summarized by the endpoints; no claim is made about interim cash demands or a real broker's margin requirement.

Explain what the roll does and does not realize

The roll closes an existing position and opens exposure at another maturity. A's profit comes from its own move from 84 to 86. B starts at its own current price of 90. Before transaction costs, the four-unit gap between A and B is not an additional realized loss on opening B. Futures entry is not an outright purchase of the underlying goods for their full notional amount.

CME's contract-roll education describes the two transactions. Campbell & Company's Deconstructing Futures Returns: The Role of Roll Yield, hosted by CME, directly addresses the mistaken immediate-loss interpretation. Attribution matters: that paper is Campbell's analysis, not an exchange-authored performance study. In the hypothetical ledger, B's loss occurs through its subsequent price move from 90 to 86, not solely because the maturity switch displayed different prices.

Distinguish convergence exposure from a guaranteed outcome

The example deliberately makes the deferred contract decline toward an unchanged spot reference during B's holding interval. That path illustrates how basis or convergence effects can matter. Actual spot prices and curve shape can both change, however. A higher deferred price does not guarantee that the eventual adjustment occurs entirely through a declining futures price; the spot reference itself might rise or the position might exit earlier.

Terms such as roll return depend on the decomposition and index methodology being used. The contract ledger is the primary calculation; a spot, basis, or roll attribution must reconcile to it under declared conventions. The four-unit curve gap is neither a universal forecast nor a standalone cash charge. Repeated maturity selection, position sizing, and the path between roll dates determine the resulting exposure.

Specify collateral, leverage, and return denominators

The spot reference rises from 80 to 86, or 7.5%. The fictional futures account falls from USD 100,000 to USD 98,000, or 2%. These are different measurements. Account return uses stated capital, not initial margin or contract notional. The same USD 2,000 loss would produce a different percentage if the strategy used a different capital allocation, even though contract-level profit and loss were unchanged.

Futures margin supports performance obligations rather than representing a full purchase payment, as the CFTC explains. Actual total returns can also include earnings on collateral and deductions for implementation costs. Do not add collateral principal as income or deduct every collateral transfer as a permanent loss. An exchange-traded commodity vehicle can introduce further fees, tracking effects, or issuer features beyond this deliberately simplified account.

Preserve a ledger rather than an ambiguous chart

A replicable analysis retains contract identifiers, quantities, multipliers, entry and exit prices, roll rules, capital allocation, and cash assumptions. Joining successive front-month quotes can introduce a maturity-switch jump that is not the held portfolio's profit or loss. A back-adjusted research series can serve another purpose, but its adjusted levels should not be treated as actual transaction prices without reconstructing the underlying positions.

This note's date marks publication of a hypothetical worked method only. No earlier model record, actual execution, or commodity forecast is implied. The useful result is a reconciled ledger: a rising spot reference, positive A profit, larger subsequent B loss, and negative 2% account return under the stated exclusions. Any further economic explanation must remain separate from those deliberately invented accounting inputs.

What to retain

• A commodity spot-price change is not automatically an investment return.
• The maturity price gap is not itself an immediate loss on opening a replacement future.
• Contract P&L, collateral effects, costs, and account capital must reconcile.

Source notes

1. CFA Institute: Introduction to Commodities and Commodity Derivatives
2. CFTC: Economic Purpose of Futures Markets and How They Work
3. CME Group: Understanding Futures Expiration & Contract Roll
4. Campbell & Company (2014), hosted by CME Group: Deconstructing Futures Returns: The Role of Roll Yield

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